Convertion apparatus and convertion method

ABSTRACT

A conversion apparatus and method is disclosed by which a file including data multiplexed therein can be edited or handled readily while maintaining the compatibility. A standard/independent conversion section converts a file of a standard AV multiplex format wherein video data and audio data are placed in a multiplexed state in a body into a file of an AV independent format wherein video data or audio data are placed collectively in a body. Meanwhile, an independent/standard conversion section converts a file of the AV independent formation into a file of the standard AV multiplex format.

BACKGROUND OF THE INVENTION

[0001] This invention relates to file conversion.

[0002] In recent years, standardization of the communication protocoland reduction in cost of communication apparatus and so forth haveproceeded, and personal computers, which include a communicationinterface (I/F) as a standard function, have been popularized.

[0003] In addition to personal computers, also broadcasting apparatusfor business use such as, for example, Audio Visual (AV) servers andVideo Tape Recorders (VTRs) are often equipped with, or are capable ofequipped with, a communication interface as a standard function. Fileexchange of video data or audio data is performed between suchbroadcasting apparatus of the type just described. It is to be notedthat video data and audio data are hereinafter referred to suitably andcollectively as AV data.

[0004] Incidentally, a file conventionally exchanged betweenbroadcasting apparatus usually has a format unique to, for example, eachmodel or each maker. Therefore, it is conventionally difficult toperform file exchange between broadcasting apparatus of different modelsor different makers.

[0005] Thus, for example, the Material Exchange Format (MXF) has beenproposed and is being standardized as a format for file exchange.

[0006] The MXF takes not only file exchange but also streaming intoconsideration and includes video data and audio data multiplexed insmall units such as frames. The MXF is described, for example, in BruceDevlin, Snell & Wilcox, G-FORS MXF document controller, “MXF informationcentre”, [online], [searched on Sep. 19, 2002], Internet, <URL:http://www.g-fors.com/mxf.htm>.

[0007] The MXF includes video data and audio data multiplexed for eachframe taking the streaming into consideration as described above.Therefore, the MXF has a subject to be solved in that it is difficult touse a broadcasting apparatus to edit video data and audio dataindependently of each other (AV independent editing) after a file of theMXF is fetched into a storage.

[0008] A method is available wherein a broadcasting apparatus converts afile of the MXF into a file of a unique format after fetching the fileof the MXF. However, if a broadcasting apparatus converts a file of theMXF into a file of a unique format quite independent of the MXF andstores the file of the unique format into a storage, then it isdifficult to handle the file on another broadcasting apparatus.

[0009] In particular, for example, a file of a unique format recorded ina storage of a certain broadcasting apparatus may be accessed from someother broadcasting apparatus through a communication interface such as,for example, the Institute of Electrical and Electronics Engineers(IEEE) or the Universal Serial Bus (USB). In this instance, however, ifthe latter broadcasting apparatus is not ready for the unique format,then it cannot handle the file of the unique format. Here, thebroadcasting apparatus cannot, for example, read out the file of theunique format.

[0010] Meanwhile, where a storage of a certain broadcasting apparatusinto which a file of a unique format is to be recorded is a removablerecording medium such as, for example, an optical disk, the removablerecording medium may be loaded into another broadcasting apparatus. Alsoin this instance, if the latter broadcasting apparatus is not ready forthe unique format, then it cannot handle the file of the unique formateither.

SUMMARY OF THE INVENTION

[0011] It is an object of the present invention to provide a conversionapparatus and a conversion method by which a file including video data,audio data, and some other data multiplexed therein can be edited orhandled readily while maintaining the compatibility.

[0012] In order to attain the object described above, according to anaspect of the present invention, there is provided a conversionapparatus for converting a file of a format including a header, a body,and a footer. The apparatus includes conversion means for converting oneof a file of a first format, which includes first and second data placedin a multiplexed state in the body thereof, and a file of a secondformat, which includes first or second data collectively placed in thebody thereof, into the other of the files.

[0013] According to another aspect of the present invention, there isprovided a conversion method for converting a file of a format includinga header, a body, and a footer. The method includes the steps ofreceiving one of a file of a first format wherein first and second dataare placed in a multiplexed state in the body and a file of a secondformat wherein first or second data are placed collectively in the body,and converting one of the file of the first format and the file of thesecond format into the other of the files.

[0014] According to a further aspect of the present invention, there isprovided a program for causing a computer to execute a conversion methodfor converting a file of a format including a header, a body, and afooter. The program includes a conversion step of converting one of afile of a first format, which includes first and second data placed in amultiplexed state in the body thereof, and a file of a second format,which includes first or second data collectively placed in the bodythereof, into the other of the files.

[0015] According to a still further aspect of the present invention,there is provided a data structure of a file of a format including aheader, a body, and a footer. The data structure includes a video filewherein a header and a footer are added to a body in which video dataare placed collectively, audio files for a plurality of channels in eachof which a header and a footer are added to a body in which audio dataof the channel are placed, and a master file describing a pointer to thevideo file and pointers to the individual audio files of the channels.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] These and other objects of the invention will be seen byreference to the description, taken in connection with the accompanyingdrawing, in which:

[0017]FIG. 1 is a block diagram showing an example of a configuration ofan AV network system to which the present invention is applied;

[0018]FIG. 2 is a diagrammatic view illustrating a standard AV multiplexformat;

[0019]FIG. 3 is a diagrammatic view illustrating an AV independentformat;

[0020]FIG. 4 is a block diagram showing an example of a configuration ofa format conversion section shown in FIG. 1;

[0021]FIG. 5 is a block diagram showing an example of a configuration ofa standard/independent conversion section shown in FIG. 4;

[0022]FIG. 6 is a block diagram showing an example of a configuration ofa video file preparation section shown in FIG. 5;

[0023]FIG. 7 is a block diagram showing an example of a configuration ofan audio file preparation section shown in FIG. 5;

[0024]FIG. 8 is a flow chart illustrating a master file preparationprocess executed by the standard/independent conversion section of FIG.5;

[0025]FIG. 9 is a flow chart illustrating a metadata file preparationprocess for a file unit executed by the standard/independent conversionsection of FIG. 5;

[0026]FIG. 10 is a flow chart illustrating a metadata file preparationprocess for a frame unit executed by the standard/independent conversionsection of FIG. 5;

[0027]FIG. 11 is a flow chart illustrating an auxiliary file productionprocess executed by the standard/independent conversion section of FIG.5;

[0028]FIG. 12 is a flow chart illustrating a video file preparationprocess executed by the standard/independent conversion section of FIG.5;

[0029]FIG. 13 is a flow chart illustrating an audio file preparationprocess executed by the standard/independent conversion section of FIG.5;

[0030]FIG. 14 is a block diagram showing an example of a configurationof an independent/standard conversion section shown in FIG. 4;

[0031]FIG. 15 is a block diagram showing an example of a video fileprocessing section shown in FIG. 14;

[0032]FIG. 16 is a block diagram showing an example of an audio fileprocessing section shown in FIG. 14;

[0033]FIG. 17 is a block diagram showing an example of a data synthesissection shown in FIG. 14;

[0034]FIG. 18 is a flow chart illustrating a metadata file processexecuted by the independent/standard conversion section shown in FIG.14;

[0035]FIG. 19 is a flow chart illustrating an auxiliary file processexecuted by the independent/standard conversion section shown in FIG.14;

[0036]FIG. 20 is a flow chart illustrating a video file process executedby the independent/standard conversion section shown in FIG. 14;

[0037]FIG. 21 is a flow chart illustrating an audio file processexecuted by the independent/standard conversion section shown in FIG.14;

[0038]FIG. 22 is a flow chart illustrating a synthesis process executedby the independent/standard conversion section shown in FIG. 14; and

[0039]FIG. 23 is a block diagram showing an example of a configurationof a computer to which the present invention is applied.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0040] Referring first to FIG. 1, there is shown an example of aconfiguration of an AV network system to which the present invention isapplied. It is to be noted that the term “system” is used to represent alogical set of a plurality of apparatus irrespective of whether or notthe components are accommodated in the same housing.

[0041] The AV network system shown includes a disk apparatus 1 which inturn includes a disk driving section 11, a format conversion section 12,and a communication interface (I/F) 13. The disk apparatus 1 receives afile of AV data transmitted through a network 4 and records the fileonto an optical disk 7. Further, the disk apparatus 1 reads out a fileof AV data recorded on the optical disk 7 and transmits the file throughthe network 4.

[0042] An optical disk 7 can be removably loaded into a disk drivingsection 11. The disk driving section 11 drives the optical disk 7 loadedtherein to record (write) a file of an AV independent format hereinafterdescribed onto the optical disk 7. Further, the disk driving section 11drives the optical disk 7 to read out a file of the AV independentformat from the optical disk 7 and supplies the file to the formatconversion section 12.

[0043] The format conversion section 12 converts the file of the AVindependent format supplied thereto from the disk driving section 11into a file of a standard AV multiplex format hereinafter described andsupplies the resulting file to the communication interface 13. Further,the format conversion section 12 converts a file of the standard AVmultiplex format supplied thereto from the communication interface 13into a file of the AV independent format and supplies the resulting fileto the disk driving section 11.

[0044] The communication interface 13 may be formed from an Institute ofElectrical and Electronics Engineers (IEEE) 1394 port, a UniversalSerial Bus (USB) port, or a Network Interface Card (NIC) for connectionof a Local Area Network (LAN). Alternatively, the communicationinterface 13 may be formed from an analog modem, a Terminal Adapter (TA)and a Digital Service Unit (DSU), an Asymmetric Digital Subscriber Line(ADSL) modem, or some other interface. The communication interface 13communicates a file of the standard AV multiplex format through thenetwork 4 such as, for example, the Internet or an intranet. Inparticular, the communication interface 13 transmits a file of thestandard AV multiplex format supplied thereto from the format conversionsection 12 through the network 4. Further, the communication interface13 receives a file of the standard AV multiplex format transmittedthereto through the network 4 and supplies the file to the formatconversion section 12.

[0045] In the disk apparatus 1 having the configuration described above,the communication interface 13 receives a file of the standard AVmultiplex format transmitted thereto through the network 4 and suppliesthe file to the format conversion section 12. The format conversionsection 12 converts the file of the standard AV multiplex format fromthe communication interface 13 into a file of the AV independent formatand supplies the resulting file to the disk driving section 11. The diskdriving section 11 records the file of the AV independent multiplexformat from the format conversion section 12 onto an optical disk 7loaded therein.

[0046] Further, in the disk apparatus 1, the disk driving section 11reads out a file of the AV independent format from an optical disk 7loaded therein and supplies the file to the format conversion section12. The format conversion section 12 converts the file of the AVindependent format from the disk driving section 11 into a file of thestandard AV multiplex format and supplies the resulting file to thecommunication interface 13. The communication interface 13 transmits thefile of the standard AV multiplex format from the format conversionsection 12 through the network 4.

[0047] A file of the standard AV multiplex format conforms to, forexample, the standards of the MXF and includes a header, a body, and afooter. Since a file of the standard AV multiplex format conforms to thestandards of the MXF, the body thereof includes video data and audiodata as AV data placed in a multiplexed state in a unit of, for example,one frame therein.

[0048] Referring to FIG. 1, AV apparatus 5 and 6 connected to thenetwork 4 are apparatus that conform to the standards of the MXF and cantherefore handle a file conforming to the standards of the MXF.Accordingly, each of the AV apparatus 5 and 6 can transmit a file of thestandard AV multiplex format to the disk apparatus 1 through the network4. Further, each of the AV apparatus 5 and 6 can receive a file of thestandard AV multiplex format transmitted thereto from the disk apparatus1. In other words, the disk apparatus 1 and the AV apparatus 5 and 6 canexchange a file of the standard AV multiplex format therebetween throughthe network 4. Further, each of the AV apparatus 5 and 6 can performvarious processes such as streaming reproduction of a received file ofthe standard AV multiplex format.

[0049] It is to be noted that an apparatus conforming to the existingstandards of the MXF like the AV apparatus 5 and 6 is hereinafterreferred to suitably as standard apparatus.

[0050] Meanwhile, a file of the AV independent format includes a header,a body, and a footer similarly as in a file of the standard AV multiplexformat. However, the body has a form different from that of the body ofa file of the standard AV multiplex format. In particular, in a file ofthe AV independent format, video data and audio data are placed indifferent files from each other. While the video file, which is a fileof video data, has a header and a footer of the same form as that of afile of the standard AV multiplex format, the body of the video fileincludes video data placed collectively therein. Also the audio file,which is a file of audio data, has a header and a footer of the formsame as that of a file of the standard AV multiplex format. However, thebody of the audio file has audio data placed collectively therein.

[0051] Accordingly, if a video file or an audio file of the AVindependent format is transmitted from the disk apparatus 1 to the AVapparatus 5 or 6, the AV apparatus 5 or 6 cannot handle video data oraudio data placed in the body of the video file or the audio file of theAV independent format unless the apparatus is ready for the AVindependent format. However, the AV apparatus 5 or 6 can handle thevideo file or the audio file itself of the AV independent format. Inparticular, the video file or the audio file of the AV independentformat is formed from a header, a body, and a footer similarly as in afile of the standard AV multiplex format, and the head and the footerhave a form same as that of a file of the standard AV multiplex format.Therefore, unless the “contents” of the body (the data placed in thebody) are referred to, the video file or the audio file itself of the AVindependent format is equivalent to a file of the standard AV multiplexformat (that is, conforms to the standard AV multiplex format).Accordingly, even if the AV apparatus 5 or 6, which is a standardapparatus, is not ready for the AV independent format, it can handle thevideo file or the audio file itself of the AV independent format.

[0052] In other words, the disk apparatus 1 and the AV apparatus 5 or 6,which is a standard apparatus, can perform file exchange of a file ofthe AV independent format.

[0053] As described above, a file of the AV independent format isequivalent to a file of the standard AV multiplex format unless the“contents” of the body of the file are referred to. From this point ofview, it can be considered that a file of the AV independent format iscompatible with a file of the standard AV multiplex format.

[0054] An optical disk 7 can be removably loaded into a disk apparatus2. The disk apparatus 2 is a standard apparatus similarly to, forexample, the AV apparatus 5 and 6, and reads out a video file or anaudio file of the AV independent format from an optical disk 7 loadedtherein and supplies the thus read out file to an editing apparatus 3.

[0055] Again, a video file or an audio file of the AV independent formatis equivalent to a file of the standard AV multiplex format unless the“contents” of the body of the file are referred to as describedhereinabove. Therefore, the disk apparatus 2, which is a standardapparatus, can read out a video file or an audio file of the AVindependent format from the optical disk 7.

[0056] The editing apparatus 3 is an apparatus that is ready for the AVindependent format and can handle a file of the AV independent format.The editing apparatus 3 performs, for example, AV independent editing ofa video file or an audio file of the AV independent format suppliedthereto from the disk apparatus 2 and supplies a video file or an audiofile of the AV independent format as a result of the editing to the diskapparatus 2.

[0057] The disk apparatus 2 records a video file or an audio file of theAV independent format supplied thereto from the editing apparatus 3 ontoan optical disk 7 loaded therein.

[0058] Once again, a video file or an audio file of the AV independentformat is equivalent to a file of the standard AV multiplex formatunless the “contents” of the body of the file are referred to asdescribed hereinabove. Therefore, the disk apparatus 2, which is astandard apparatus, can record a video file or an audio file of the AVindependent format onto the optical disk 7.

[0059] As described hereinabove, in a file of the standard AV multiplexformat, video data and audio data are placed in a multiplexed state, forexample, in a unit of a frame in the body. Meanwhile, in a video file oran audio file of the AV independent format, video data or audio data areplaced collectively in the body. Therefore, editing such as AVindependent editing of a video file or an audio file of the AVindependent format can be performed readily. Further, since a file ofthe AV independent format has a header and a footer of the same form asthat of a file of the standard AV multiplex format, it is compatiblewith a file of the standard AV multiplex format unless the “contents” ofthe body are referred to. Consequently, a file of the AV independentformat can be handled by a standard apparatus.

[0060]FIG. 2 shows an example of the standard AV multiplex format.

[0061] More particularly, FIG. 2 illustrates a standard AV multiplexformat, which adopts video data coded in accordance with the MovingPicture Experts Group (MPEG) IMX method called D10 as video data placedin the body. Further, the standard AV multiplex format illustratedadopts non-compressed audio data of the Audio Engineering Society (AES)3 form as audio data placed in the body.

[0062] It is to be noted that other video data and audio data of variousformats such as a format of the Digital Video (DV) standards can beplaced in the body alternatively.

[0063] A file of the standard AV multiplex format is formed from aheader (File Header), a body (File Body), and a footer (File Footer)placed in order from the top therein.

[0064] The header includes a Header Partition Pack, Header Metadata andan Index Table placed in order from the top therein. The head partitionpack includes data for specifying the header, the form of data placed inthe body, information representative of a file format, and so forthplaced therein. The header metadata includes metadata of a file unitplaced therein. The metadata includes, for example, a preparation dateof the file, and information regarding data placed in the body. Theindex table includes a table placed therein. The table indicates thepositions of edit units hereinafter described, which are placed in thebody.

[0065] It is to be noted that the index table is provided optionally andmay be or may not be included in the header. Further, the header canplace various optional data therein in addition to the index table.

[0066] Meanwhile, as the information representative of the file formatplaced in the header partition pack, information representative of thestandard AV multiplex format is adopted in a file of the standard AVmultiplex format. However, information representative of the AVindependent format is adopted by a file of the AV independent format. Itis to be noted that the form itself of the header partition pack iscommon between the standard AV multiplex format and the AV independentformat.

[0067] The footer is formed from a Footer Partition Pack in which datafor specifying the footer and so forth are placed.

[0068] The body is formed from more than one edit unit. An edit unit isa unit of a frame and includes AV data for one frame placed therein.

[0069] In particular, an edit unit includes a system item, a pictureitem, a sound item, and an auxiliary item placed in order from the toptherein.

[0070] The system item includes metadata (metadata of a frame unit)regarding a frame of video data placed in the succeeding picture item.The metadata of a frame unit may be, for example, a time code.

[0071] The picture item includes video data for one frame placedtherein. In FIG. 2, video data of the D10 format described hereinaboveare placed in the picture item.

[0072] In particular, video data for one frame having a Key, Length, andValue (KLV) structure is planed in the picture item by KLV-coding.

[0073] The KLV structure signifies a structure wherein a Key, a Length,and a Value are placed in order from the top. The key has a label of 16bytes placed therein. The label conforms to the standards of the SMPTE298M and represents what data are placed in the value. The length hasplaced therein a data length of data placed in the Value. The value hereincludes video data of one frame placed therein.

[0074] The picture item uses a fixed data length whose reference is aKLV Alignment Grid (KAG). In order that the picture item may have afixed length, also a Filler as data for stuffing is provided with a KLVstructure similarly and placed next to the video data of the pictureitem.

[0075] It is to be noted that the fixed length, which is a data lengthof the picture item and for which the KAG is used as a reference, is setto an integral number of times the sector length of the optical disk 7such as, for example, 512 bytes or 2 Kbytes. In this instance, theoptical disk 7 and the picture item exhibit high affinity, andconsequently, reading/writing processing from/to the optical disk 7 canbe performed at a high speed.

[0076] Not only the system item described above but also a sound itemand an auxiliary item hereinafter described adopt the KLV structuresimilarly to the picture item, and the data length is a fixed lengthwhose reference is the KAG.

[0077] The sound item includes audio data placed in a KLV structureplaced therein similarly as in the picture item described above. Theaudio data in this instance corresponds to one frame of the video dataplaced in the picture item.

[0078] Further, the sound item has audio data of a plurality ofchannels, for example, eight channels placed in a multiplexed statetherein.

[0079] In particular, the Value of the KLV structure of the sound itemincludes an element header EH, an audio sample Count ASC, a stream validflag SVF, and multiplexed audio data of eight channels placed in orderfrom the top therein.

[0080] In the sound item, the audio data of eight channels aremultiplexed by placing samples of the audio data in such an order asfirst samples, second samples, . . . of the audio data of the eightchannels in one frame. Each of numerals in parentheses of the audio datadisplayed at the lowest portion of FIG. 2 represents what numbered onethe sample of the audio data is.

[0081] The element header EH has placed therein data for specifying anelement header and so forth. The audio sample count ASC has placedtherein the number of samples of the audio data placed in the sounditem. The stream valid flag SVF is formed from eight bits (one byte),and each bit thereof represents whether the audio data of the channelcorresponding to the bit is valid or invalid. In particular, each of thebits of the stream valid flag SVF typically has the value of one wherethe audio data of the channel corresponding to the bit is valid, but hasthe value of zero where the audio data is invalid.

[0082] The auxiliary item has necessary user data placed therein.Accordingly, the auxiliary item is an area into which the user can placearbitrary data.

[0083] As described above, in the standard AV multiplex format, thesystem item in which metadata of the frame unit is placed, the pictureitem in which video data is placed, the sound item in which audio dataare placed, and the auxiliary item in which user data are placed aremultiplexed in a unit of one frame. Further, in the sound item, audiodata of eight channels are multiplexed in the unit of one sample.

[0084] Where a file in which video data and audio data are placedcollectively but separately is used, reproduction of the video data andthe audio data cannot be started until after all of the file of thevideo data and the file of the audio data collected in this manner arereceived. However, where the standard AV multiplex format is used, sincevideo data and audio data are multiplexed in a unit of a frame, if videodata and audio data for one frame are received, then the video data andthe audio data of the frame can be reproduced immediately. Accordingly,it is considered that the standard AV multiplex format is suitable forstreaming.

[0085] As described above, the standard AV multiplex format is suitablefor streaming because video data and audio data are multiplexed in aunit of a frame. However, the standard AV multiplex format is notsuitable for AV independent editing wherein video data and audio dataare edited independently of each other.

[0086] Further, also metadata of a file unit exist discretely in thesystem item of the edit unit. The metadata discrete in the system arehard to handle.

[0087] Further, the AES3 form, which can be adopted by the standard AVmultiplex format, is specified such that at least four bytes areallocated to one sample of audio data. Therefore, the entire file has agreat size.

[0088]FIG. 3 illustrates an example of an AV independent format.

[0089] Referring to FIG. 3, in the AV independent format illustrated,video data, audio data, metadata in a file unit, and user data, whichare multiplexed in the standard AV multiplex format, are formed as filesin which they are individually placed collectively.

[0090] In particular, in the AV independent format, picture items inwhich video data are placed in the standard AV multiplex format areplaced collectively in the body, and a header and a footer having thesame form as that of the standard AV multiplex format are added to thebody to form a video file.

[0091] It is to be noted that, since the body of a video file of the AVindependent format has placed therein picture items each having a lengthequal to an integral number of times the sector length of the opticaldisk 7, also the entire body has a size equal to an integral number oftimes the sector length of the optical disk 7. In other words, the bodyof a video file of the AV independent format has a size, which exhibitssector alignment.

[0092] Further, while the index table shown in FIG. 2 is shown in theheader of the file of the standard AV multiplex format, according to theMXF, the index table is optional. Thus, the video file shown in FIG. 3does not adopt the index table. This similarly applies to audio fileshereinafter described.

[0093] In the AV independent format, multiplexed audio data of eightchannels placed in the sound items in the standard AV multiplex formatare demultiplexed in audio data for the individual channels. Thus, audiodata whose form has been converted from the AES3 format into the WAVEform are placed in the KLV structure in the body of a file of eachchannel. A header and a footer of the form same as that of the standardAV multiplex format are added to the body to form an audio file.

[0094] In particular, in the AV independent format, audio files foreight channels are formed independently of each other for audio data ofthe eight channels. An audio file for each channel is formed byprocessing the audio data of the channel so as to have the WAVE form andthe KLV structure, placing the processed audio data collectively intothe body, and then adding a header and a footer of the form same as thatof the standard AV multiplex format to the body.

[0095] It is to be noted that, while the body of an audio file of the AVindependent format has placed therein audio data of the WAVE form of acertain channel collected so as to have the KLV structure as describedabove, the entire audio data may not necessarily have a size equal to aplural number of times the sector length of the optical disk 7.Therefore, in order to establish sector alignment, a filler of the KLVstructure necessary to establish sector alignment is placed next to theaudio data of the KLV structure in the body of an audio file of the AVindependent format.

[0096] The AV independent format includes the following files inaddition to such a video file and audio files individually for eightchannels as described above. In particular, the AV independent formatfurther includes a metadata file of file units in which metadata of fileunits placed in the head metadata in the standard AV multiplex formatare placed collectively. The AV independent format further includes ametadata file of frame units in which system items in which metadata offrame units are placed in the standard AV multiplex format are placedcollectively. Furthermore, the AV independent format includes anauxiliary file wherein auxiliary items in which user data are placed inthe standard AV multiplex format are placed collectively.

[0097] In addition, the AV independent format includes a master file inwhich pointers to a video file, audio files individual for eightchannels, a metadata file of file units, a metadata file of frame unitsand an auxiliary file are described.

[0098] More particularly, the master file is described, for example, inthe Extensible Markup Language (XML). In the master file, for example,file names of a video file, audio files individual for eight channels, ametadata file of file units, a metadata file of frame units, and anauxiliary file are described as pointers to the files.

[0099] Accordingly, the video file, audio files individual for eightchannels, metadata file of file units, metadata file of frame units, andauxiliary file can be referred to from the master file.

[0100] It is to be noted that, for example, the auxiliary file may be anoptional file.

[0101] It is to be noted that the metadata file of file units, metadatafile of frame units and the auxiliary file illustrated in FIG. 3 do nothave a header and a footer of the form same as that of the standard AVmultiplex format. However, a header and a footer of the form same asthat of the standard AV multiplex format may otherwise be added to themetadata file of file units, metadata file of frame units, and theauxiliary file.

[0102] Further, the header metadata, which forms the header of a videofile and a header file of the AV independent format, has metadata offile units of a minimum set placed therein.

[0103] In particular, the AV independent format includes metadata filesof file units wherein metadata of file units placed in the headermetadata are placed in the standard AV multiplex format. Therefore, itis redundant to place the metadata of file units placed in the metadatafiles in an overlapping relationship with the header metadata, whichform the header of the video file and audio files. Further, this makesthe size of the entire file of the AV independent format great.

[0104] However, in the MXF, the header metadata is an item essentiallyrequired for the header, and if a header is formed without placingheader metadata therein, then the resulting header does not have thesame form as that of the standard AV multiplex format.

[0105] Meanwhile, in the MXF, metadata of file units to be placed in theheader metadata includes various items. However, some of the items areessentially required, but the other items are optional.

[0106] Therefore, in order to prevent the file size from becoming greatand maintain the compatibility with the standard AV multiplex format,the header metadata, which form the header of the video file and theaudio files of the AV independent format, has metadata of file units ofa minimum set placed therein. More particularly, metadata only of thoseitems whose placement in the header metadata is essentially required inthe MXF are placed in the header metadata of the video file and theaudio files of the AV independent format.

[0107] As described above, in the AV independent format, video data areplaced collectively in the video file, and audio data of individualchannels are collectively placed in the audio files for the individualchannels. Therefore, editing such as AV independent editing whereinvideo data and audio data are edited independently of each other can beperformed readily.

[0108] Furthermore, in the AV independent format, since audio data havethe WAVE format, the data amount can be reduced when compared with analternative case wherein audio data of the AES3 form are adopted as inthe standard AV independent format. As a result, when a file of the AVindependent format is recorded onto a storage such as the optical disk7, the capacity of the storage necessary for the recording can bereduced when compared with an alternative case wherein a file of thestandard AV multiplex format is recorded.

[0109] Further, a video file and audio files of the AV independentformat include a header, a body, and a footer disposed in order from thetop similarly to a file of the standard AV multiplex format, and theheader and the footer are placed in a form same as that of the standardAV multiplex form. Therefore, if a video file and audio files of the AVindependent format are recorded onto a removable optical disk 7 by thedisk apparatus 1 and the optical disk 7 is loaded into the diskapparatus 2, then if the disk apparatus 2 is a standard apparatus (onwhich a file of the MXF can be handled), then the apparatus 2 can readout the video file and the audio files of the AV independent format fromthe optical disk 7.

[0110] Further, in the AV independent format, metadata of file units andmetadata of frame units are collected separately each into differentfiles. This facilitates a search process in which metadata is used.

[0111]FIG. 4 shows an example of a configuration of the formatconversion section 12 of the disk apparatus 1 of FIG. 1.

[0112] Referring to FIG. 4, the format conversion section 12 shownincludes a standard/independent conversion section 21 and anindependent/standard conversion section 22.

[0113] The standard/independent conversion section 21 converts a file ofthe standard AV multiplex format of FIG. 2 supplied thereto from thecommunication interface 13 into a file of the AV independent format ofFIG. 3 and supplies the resulting file to the disk driving section 11.The independent/standard conversion section 22 converts a file of the AVindependent format of FIG. 3 supplied thereto from the disk drivingsection 11 into a file of the standard AV multiplex format of FIG. 2 andsupplies the resulting file to the communication interface 13.

[0114]FIG. 5 shows an example of a configuration of thestandard/independent conversion section 21 shown in FIG. 4.

[0115] Referring to FIG. 5, a file of the standard AV multiplex formatis supplied from the communication interface 13 to a buffer 31. Thebuffer 31 temporarily stores the file of the standard AV multiplexformat supplied thereto.

[0116] After the file of the standard AV multiplex format is stored intothe buffer 31, a master file preparation section 32 prepares a masterfile of the AV independent format from the file of the standard AVmultiplex format and supplies the prepared file to a buffer 44.

[0117] A header acquisition section 33 extracts a header from the fileof the standard AV multiplex format stored in the buffer 31 to acquirethe header and supplies the header to a header metadata extractionsection 35.

[0118] A body acquisition section 34 extracts a body from the file ofthe standard AV multiplex format stored in the buffer 31 to acquire thebody and supplies the body to a system item extraction section 36, anauxiliary item extraction section 38, a picture item extraction section40, and a sound item extraction section 42.

[0119] The header metadata extraction section 35 extracts headermetadata from the header supplied thereto from the header acquisitionsection 33 and supplies metadata of file units placed in the headermetadata to a metadata file preparation section 37. The system itemextraction section 36 extracts system items in which the metadata offrames are placed from edit units of the body supplied thereto from thebody acquisition section 34 and supplies the system items to themetadata file preparation section 37. The metadata file preparationsection 37 prepares a metadata file of file units in which the metadataof file units supplied thereto from the header metadata extractionsection 35 are placed. The metadata file preparation section 37 furtherprepares a metadata file of frame units in which the system items of theedit units supplied thereto from the system item extraction section 36are collectively and sequentially placed. The metadata file preparationsection 37 supplies the metadata files of file units and frame units tothe buffer 44.

[0120] The auxiliary item extraction section 38 extracts auxiliary itemsin which user data of frame units are placed from the edit units of thebody supplied thereto from the body acquisition section 34 and suppliesthe extracted auxiliary items to an auxiliary file preparation section39. The auxiliary file preparation section 39 prepares an auxiliary filein which the auxiliary items of the edit units supplied thereto from theauxiliary file preparation section 39 are collectively placed andsupplies the auxiliary file to the buffer 44.

[0121] The picture item extraction section 40 extracts picture items inwhich video data of frame units are placed from the edit units of thebody supplied thereto from the body acquisition section 34 and suppliesthe picture items to a video file preparation section 41. The video filepreparation section 41 prepares a file in which the picture items of theedit units supplied thereto from the picture item extraction section 40are placed collectively in the body and a header and a footer of a formsame as that of a file of the standard AV multiplex format are added tothe body. The video file preparation section 41 supplies the thusprepared file to the buffer 44.

[0122] The sound item extraction section 42 extracts sound items inwhich audio data of frame units are placed from the edit units of thebody supplied thereto from the body acquisition section 34 and suppliesthe sound item to an audio file preparation section 43. The audio filepreparation section 43 prepares an audio file for each channel in whichaudio data of the channel placed in the sound items of the edit unitssupplied thereto from the sound item extraction section 42 are placedcollectively for the channel in the body and a header and a footer of aform same as that of a file of the standard AV multiplex format areadded to the body. The audio file preparation section 43 supplies theaudio files for the channels prepared in this manner to the buffer 44.

[0123] The buffer 44 temporarily stores the master file supplied theretofrom the master file preparation section 32, the metadata files of fileunits and frame units supplied thereto from the metadata filepreparation section 37, and the auxiliary file supplied thereto from theauxiliary file preparation section 39. Further, the buffer 44temporarily stores the video file supplied thereto from the video filepreparation section 41 and the audio files for the channels suppliedthereto from the audio file preparation section 43. Then, the buffer 44supplies the stored files as files of the AV independent format to thedisk driving section 11.

[0124]FIG. 6 shows an example of a configuration of the video filepreparation section 41 shown in FIG. 5.

[0125] Referring to FIG. 6, a picture item of each edit unit suppliedfrom the picture item extraction section 40 is received by a couplingsection 51. The coupling section 51 successively couples or connectspicture items of edit units successively supplied thereto and suppliesthe picture items to a header/footer addition section 52. Theheader/footer addition section 52 adds a header and a footer of a formsame as that of a file of the standard AV multiplex format to a bodyprovided by the picture items of the edit units coupled to each otherand supplied thereto from the coupling section 51 to form a video fileof the AV independent format. Then, the header/footer addition section52 outputs the video file of the AV independent format.

[0126]FIG. 7 shows an example of a configuration of the audio filepreparation section 43 shown in FIG. 5.

[0127] Referring to FIG. 7, a sound item of each edit unit supplied fromthe sound item extraction section 42 is received by a KLV decoder 61.The KLV decoder 61 decomposes the KLV structure of audio data placed inthe sound items of the edit units to obtain multiplexed audio data ofeight channels (such data is hereinafter referred to suitably asmultiplexed audio data) and supplies the multiplexed audio data to achannel demultiplexing section 62.

[0128] The channel demultiplexing section 62 demultiplexes themultiplexed audio data of sound items supplied thereto from the KLVdecoder 61 into audio data of individual channels and supplies the audiodata of the channels collectively for the individual channels to a dataconversion section 63.

[0129] The data conversion section 63 converts the coding method of theaudio data of the channels supplied thereto from the channeldemultiplexing section 62. In particular, while audio data in thestandard AV multiplex format are in a form encoded by the AES3 form, theaudio data in the AV independent format are in another form encoded bythe WAVE system. Therefore, the data conversion section 63 converts theaudio data (audio data of the AES3 form) encoded by the AES3 method intoaudio data (audio data of the WAVE system) encoded by the WAVE system.

[0130] It is to be noted that, while the data conversion section 63 hereconverts audio data of the AES3 system into audio data of the WAVEsystem, the section 63 can convert the audio data into audio data of asystem other than the WAVE system. In particular, the conversion ofaudio data by the data conversion section 63 is performed for the objectof suppressing the data amount of audio data of the AES3 system.Therefore, the data conversion section 63 may adopt any coding systemonly if the coding system can achieve the object just described.

[0131] On the other hand, where the data amount of audio data does notmatter, the audio file preparation section 43 can be configured withoutprovision of the data conversion section 63.

[0132] The audio data of the individual channels of the WAVE systemobtained by the data conversion section 63 are supplied to a KLV encoder64. The KLV encoder 64 KLV-encodes the audio data supplied thereto fromthe data conversion section 63 and collected for the individual channelsinto audio data of the KLV structure. Then, the KLV encoder 64 adds afiller (FIG. 3) necessary for establishment of sector alignment to theaudio data of each channel of the KLV structure and supplies theresulting audio data of the channels to a header/footer addition section65.

[0133] The header/footer addition section 65 adds a header and a footerof a form same as that of a file of the standard AV multiplex format tothe body of each channel, which includes the audio data of the channelsupplied thereto from the KLV encoder 64, to produce an audio file foreach channel of the AV independent format. Then, the header/footeraddition section 65 outputs the audio files of the individual channelsof the AV independent format.

[0134] Referring back to FIG. 5, the standard/independent conversionsection 21 performs a master file preparation process for preparing amaster file as a file of the AV independent format, a metadata filepreparation process for preparing metadata files of file units and frameunits, and an auxiliary file preparation process for preparing anauxiliary file. The standard/independent conversion section 21 furtherperforms a video file preparation process for preparing a video file andan audio file preparation process for preparing audio files.

[0135] Thus, the master file preparation process, metadata filepreparation process, auxiliary file preparation process, video filepreparation process, and audio file preparation process executed by thestandard/independent conversion section 21 are described below withreference to flow charts of FIGS. 8 to 13.

[0136] First, the master file preparation process is described withreference to the flow chart of FIG. 8.

[0137] The master file preparation is started, for example, when a fileof the standard AV multiplex format is supplied to and stored into thebuffer 31 (FIG. 5). Thus, first at step S1, the master file preparationsection 32 (FIG. 5) produces file names for metadata files of file unitsand frame units, an auxiliary file, a video file, and audio files forindividual channels. Then, the processing advances to step S2. At stepS2, the master file preparation section 32 prepares a master file inwhich a link to a file of each of the file names produced at step S1 isdescribed in the XML and supplies the master file to the buffer 44 sothat the master file is stored into the buffer 44. The master filepreparation process is ended thereby.

[0138] Now, the metadata file preparation process for file units forpreparing a metadata file of file units is described with reference tothe flow chart of FIG. 9.

[0139] For example, if a file of the standard AV multiplex format issupplied to and stored into the buffer 31 (FIG. 5), then the metadatafile preparation process for file units is started. First at step S11,the header acquisition section 33 acquires the header from the file ofthe standard AV format stored in the buffer 31 and supplies the headerto the header metadata extraction section 35. Then, the processingadvances to step S12. At step S12, the header metadata extractionsection 35 extracts header metadata from the header supplied theretofrom the header acquisition section 33 and supplies the header metadataof file units placed in the header metadata to the metadata filepreparation section 37. Then, the processing advances to step S13. Atstep S13, the metadata file preparation section 37 prepares a metadatafile of file units in which the metadata of file units supplied theretofrom the header metadata extraction section 35 are placed, and suppliesthe metadata file of file units to the buffer 44 so that the metadatafile of file units may be stored into the buffer 44. The metadatapreparation process for file units is ended thereby.

[0140] Now, the metadata file preparation process for frame unitswherein a metadata file of frame units is prepared is described withreference to the flow chart of FIG. 10.

[0141] For example, if a file of the standard AV multiplex format isstored into the buffer 31 (FIG. 5), then the metadata file preparationprocess for frame units is started. First at step S21, the bodyacquisition section 34 acquires the body from the file of the standardAV multiplex format stored in the buffer 31 and supplies the body to thesystem item extraction section 36. Then, the processing advances to stepS22. At step S22, the system item extraction section 36 extracts systemitems in which metadata of frame units are placed from edit units of thebody supplied thereto from the body acquisition section 34 and suppliesthe system items to the metadata file preparation section 37. Then, theprocessing advances to step S23. At step S23, the metadata filepreparation section 37 couples the system items of the edit unitssupplied from the system item extraction section 36 to prepare ametadata file of frame units in which the system items of the edit unitsare collectively placed. Then, the metadata file preparation section 37supplies the metadata file of frame units to the buffer 44 so that themetadata file of frame units is stored into the buffer 44. The metadatafile preparation process for a frame unit is ended thereby.

[0142] Subsequently, the auxiliary file preparation process forpreparing an auxiliary file is described with reference to the flowchart of FIG. 11.

[0143] For example, if a file of the standard AV multiplex format issupplied to the buffer 31 (FIG. 5), then the auxiliary file preparationprocess is stared. First at step S31, the body acquisition section 34acquires the body from the file of the standard AV multiplex formatstored in the buffer 31 and supplies the body to the auxiliary itemextraction section 38. Then, the processing advances to step S32. Atstep S32, the auxiliary item extraction section 38 extracts auxiliaryitems from edit units of the body supplied thereto from the bodyacquisition section 34 and supplies the extracted auxiliary items to theauxiliary file preparation section 39. Then, the processing advances tostep S33. At step S33, the auxiliary file preparation section 39 couplesthe auxiliary items of the edit units supplied thereto from theauxiliary item extraction section 38 to prepare an auxiliary file inwhich the auxiliary items of the edit units are placed collectively.Then, the auxiliary file preparation section 39 supplies the auxiliaryfile to the buffer 44 so that the auxiliary file is stored into thebuffer 44. The auxiliary file preparation process is ended thereby.

[0144] Now, the video file preparation process for preparing a videofile is described with reference to the flow chart of FIG. 12.

[0145] For example, if a file of the standard AV multiplex format issupplied to and stored into the buffer 31 (FIG. 5), then the video filepreparation process is started. First at step S41, the body acquisitionsection 34 acquires the body from the file of the standard AV multiplexformat stored in the buffer 31 and supplies the body to the picture itemextraction section 40. Then, the processing advances to step S42. Atstep S42, the picture item extraction section 40 extracts picture itemsfrom edit units of the body supplied thereto from the body acquisitionsection 34 and supplies the extracted picture items to the video filepreparation section 41. Then, the processing advances to step S43. Atstep S43, the video file preparation section 41 (FIG. 6) couples thepicture items of the edit units supplied thereto from the picture itemextraction section 40 to produce a body in which the picture items ofthe edit units are collectively placed and supplies the produced body tothe header/footer addition section 52. Then, the processing advances tostep S44.

[0146] At step S44, the header/footer addition section 52 adds a headerand a footer of a form same as that of the file of the standard AVmultiplex format to the body supplied thereto from the coupling section51 to prepare a video file of the AV independent format. Then, theheader/footer addition section 52 supplies the video file of the AVindependent format to the buffer 44 so that the video file is storedinto the buffer 44. The video file preparation process is ended thereby.

[0147] Now, the audio file preparation process for preparing audio filesis described with reference to the flow chart of FIG. 13.

[0148] For example, if a file of the standard AV multiplex format issupplied to and stored into the buffer 31 (FIG. 5), then the audio filepreparation process is started. First at step S51, the body acquisitionsection 34 acquires the body from the file of the standard AV multiplexformat stored in the buffer 31 and supplies the body to the sound itemextraction section 42. Then, the processing advances to step S52. Atstep S52, the sound item extraction section 42 extracts sound items fromedit units of the body supplied thereto from the body acquisitionsection 34 and supplies the extracted sound items to the audio filepreparation section 43. Then, the processing advances to step S53. Atstep S53, the audio file preparation section 43 (FIG. 7) decomposes theKLV structure of the audio data placed in the sound items of the editunits to obtain multiplexed audio data of eight channels. Then, theaudio file preparation section 43 supplies the multiplexed audio data tothe channel demultiplexing section 62. Thereafter, the processingadvances to step S54.

[0149] At step S54, the channel demultiplexing section 62 demultiplexesthe multiplexed audio data of the sound items supplied thereto from theKLV decoder 61 to form audio data of the AES3 form for the individualchannels. Then, the channel demultiplexing section 62 collectivelyplaces the audio data of the AES3 form for the individual channels andsupplies the resulting audio data to the data conversion section 63.

[0150] Then, the processing advances to step S55, at which the dataconversion section 63 converts the audio data of the AES3 of theindividual channels supplied thereto from the channel demultiplexingsection 62 into audio data of the WAVE form and supplies the audio dataof the WAVE form to the KLV encoder 64. Then, the processing advances tostep S56. At step S56, the KLV encoder 64 KLV-encodes the audio data ofthe WAVE form collected for the individual channels and received fromthe data conversion section 63 into audio data of the KLV structure.Further, the KLV encoder 64 adds a filler (FIG. 23) necessary toestablish sector alignment to the audio data of each of the channelshaving the KLV structure. Consequently, the KLV encoder 64 produces abody for each channel in which the audio data of the WAVE form of thechannel are placed collectively, and besides a required filler isplaced. The KLV encoder 64 supplies the thus produced bodies to theheader/footer addition section 65. Thereafter, the processing advancesto step S57.

[0151] At step S57, the header/footer addition section 65 adds a headerand a footer of a form same as that of the file of the standard AVmultiplex format to the body of each of the channels supplied theretofrom the KLV encoder 64 to prepare an audio file of the AV independentformat for the channel. Then, the header/footer addition section 65supplies the audio files of the AV independent format for the individualchannels to the buffer 44 so that the audio files are stored into thebuffer 44. The audio file preparation process is ended thereby.

[0152]FIG. 14 shows an example of a configuration of theindependent/standard conversion section 22 of FIG. 4.

[0153] Referring to FIG. 14, a buffer 101 temporarily stores files ofthe AV independent format supplied thereto from the disk driving section11 (FIG. 1). The files include a master file, a metadata file of fileunits, a metadata file of frame units, an auxiliary file, a video file,and audio files for eight channels.

[0154] A file acquisition section 102 refers to the master file storedin the buffer 101 to recognize the file names of the metadata file offile units, metadata file of frame units, auxiliary file, video file,and audio files for eight channels. Then, the buffer 101 accesses thedisk driving section 11 through the buffer 101 to read out the metadatafile of file units, metadata file of frame units, auxiliary file, videofile, and audio files for eight channels from the optical disk 7 basedon the recognized file names to acquire the files. Then, the fileacquisition section 102 supplies the metadata file of file units and themetadata file of frame units thus acquired to a metadata file processingsection 103. Further, the file acquisition section 102 supplies theauxiliary file to an auxiliary file processing section 104, supplies thevideo file to a video file processing section 105, and supplies theaudio files for eight channels to an audio file processing section 106.

[0155] The metadata file processing section 103 extracts metadata offile units from within the metadata file of file units supplied theretofrom the file acquisition section 102. Further, the metadata fileprocessing section 103 extracts system items in which the metadata offrame units are placed from within the metadata file of frame units.Then, the metadata file processing section 103 supplies the metadata offile units and the system items to a data synthesis section 107.

[0156] The auxiliary file processing section 104 extracts auxiliaryitems from within the auxiliary file supplied thereto from the fileacquisition section 102 and supplies the auxiliary items to the datasynthesis section 107.

[0157] The video file processing section 105 extracts picture items fromwithin the video file supplied thereto from the file acquisition section102 and supplies the picture items to the data synthesis section 107.

[0158] The video file processing section 105 extracts audio data of theindividual channels from within the audio files of the eight channelssupplied thereto from the file acquisition section 102 and producessound items in which the audio data of the individual channels areplaced in a multiplexed state. The video file processing section 105supplies the sound items to the data synthesis section 107.

[0159] The data synthesis section 107 receives the metadata of fileunits and the system items supplied thereto from the metadata fileprocessing section 103, the auxiliary items supplied thereto from theauxiliary file processing section 104, the picture items suppliedthereto from the video file processing section 105, and the sound itemssupplied thereto from the audio file processing section 106. Then, thedata synthesis section 107 uses the received items to prepare a file ofthe standard AV multiplex format and supplies the file of the standardAV multiplex format to a buffer 108.

[0160] The buffer 108 temporarily stores the file of the standard AVmultiplex format supplied thereto from the data synthesis section 107and supplies the file to the communication interface 13 (FIG. 1).

[0161]FIG. 15 shows an example of a configuration of the video fileprocessing section 105 shown in FIG. 14.

[0162] A video file supplied from the file acquisition section 102 isreceived by a header/footer removal section 111. The header/footerremoval section 111 removes a header and a footer from the video filereceived thereby and supplies the remaining body to a decompositionsection 112. The decomposition section 112 separates a sequence ofpicture items placed in the body supplied thereto from the header/footerremoval section 111 and extracts, from within the sequence, units to bemultiplexed with other items (system items, sound items, and auxiliaryitems), that is, the individual items in which video data of frame unitsare placed. Then, the decomposition section 112 supplies the pictureitems to the data synthesis section 107 (FIG. 4).

[0163]FIG. 16 shows an example of a configuration of the audio fileprocessing section 106 shown in FIG. 14.

[0164] Audio files of eight channels supplied from the file acquisitionsection 102 are received by a header/footer removal section 121. Theheader/footer removal section 121 removes a header and a footer fromeach of the audio files of eight channels received thereby and suppliesthe remaining bodies of the channels to a KLV decoder 122.

[0165] The KLV decoder 122 decomposes the KLV structure of the bodies ofthe channels supplied thereto from the header/footer removal section 121and supplies the audio data of the WAVE form of the channels obtained bythe decomposition to a data conversion section 123.

[0166] The data conversion section 123 performs inverse conversion tothat executed by the data conversion section 63 of FIG. 7 for the audiodata supplied thereto from the KLV decoder 122. In particular, the dataconversion section 123 converts the audio data of the channels of theWAVE form supplied thereto from the KLV decoder 122 into audio data ofthe channels of the AES3 form and supplies the audio data of thechannels of the AES3 form to a channel multiplexing section 124.

[0167] The channel multiplexing section 124 multiplexes the audio dataof the channels supplied thereto from the channel multiplexing section124 in a unit of a sample and supplies multiplexed audio data obtainedby the multiplexing to a KLV encoder 125.

[0168] The KLV encoder 125 delimits the multiplexed audio data suppliedthereto from the channel multiplexing section 124 in a unitcorresponding to each frame of the video data and KLV-encodes themultiplexed audio data corresponding to each frame so as to have a KLVstructure. Further, the KLV encoder 125 adds, to the KLV structure ofthe multiplexed audio data corresponding to each frame, a KLV structureof a filler of a length corresponding to a shortage from the data lengthof a sound item, which is a fixed length, thereby to form a sound item.Then, the KLV encoder 125 supplies the thus formed sound item to thedata synthesis section 107 (FIG. 14).

[0169]FIG. 17 shows an example of a configuration of the data synthesissection 107 shown in FIG. 14.

[0170] A header/footer production section 131 receives metadata of fileunits outputted from the metadata file processing section 103. Theheader/footer production section 131 produces a header and a footer of afile of the standard AV multiplex format and places the metadata of fileunits from the metadata file processing section 103 into the headermetadata of the header. Then, the header/footer production section 131supplies the header and the footer to a header/footer addition section133.

[0171] A multiplexing section 132 receives system items outputted fromthe metadata file processing section 103, auxiliary items outputted fromthe auxiliary file processing section 104, picture items outputted fromthe video file processing section 105, and sound items outputted fromthe audio file processing section 106. The multiplexing section 132successively multiplexes the system items, picture items, sound items,and auxiliary items supplied thereto in this order to form a sequence ofedit units. Then, the multiplexing section 132 supplies the sequence ofedit units as a body to the header/footer addition section 133.

[0172] The header/footer addition section 133 adds the header and thefooter supplied thereto from the header/footer production section 131 tothe body supplied thereto from the multiplexing section 132 to form afile of the standard AV multiplex format. As a result, the section 133outputs the file of the standard AV multiplex format.

[0173] Referring back to FIG. 14, the independent/standard conversionsection 22 performs a metadata file process for processing a metadatafile, an auxiliary file process for processing an auxiliary file, avideo file process for processing a video file, and an audio fileprocess for processing audio files. The independent/standard conversionsection 22 further performs a synthesis process for preparing a file ofthe standard AV multiplex format through synthesis using results of theprocesses mentioned above.

[0174] The metadata file process, auxiliary file process, video fileprocess, audio file process, and synthesis process performed by theindependent/standard conversion section 22 are described below withreference to flow charts of FIGS. 18 to 22.

[0175] First, the metadata file process is described with reference tothe flow chart of FIG. 18.

[0176] The metadata file process is started, for example, when a masterfile is read out from an optical disk 7 by the disk driving section 11and stored into the buffer 101.

[0177] First, at step S101, the file acquisition section 102 refers tothe master file stored in the buffer 101 to recognize the file names ofthe metadata files of file units and frame units. Further, at step S101,the file acquisition section 102 accesses the disk driving section 11 toread out the metadata files of file units and frame units from theoptical disk 7 based on the file names through the buffer 101 to acquirethe files. Then, the file acquisition section 102 supplies the acquiredmetadata files to the metadata file processing section 103. Then, theprocessing advances to step S102. At step S102, the metadata fileprocessing section 103 extracts, from within the metadata file of thefile units supplied thereto from the file acquisition section 102, themetadata of file units. Further, the metadata file processing section103 extracts, from within the metadata file of the frame units, systemitems in which the metadata of the frame units are placed. Then, themetadata file processing section 103 supplies the extracted metadata offile units and the system items to the data synthesis section 107. Themetadata file process is ended thereby.

[0178] Now, the auxiliary file process is described with reference tothe flow chart of FIG. 19.

[0179] The auxiliary file process is started, for example, when a masterfile is read out from an optical disk 7 by the disk driving section 11and stored into the buffer 101.

[0180] First at step S111, the file acquisition section 102 refers tothe master file stored in the buffer 101 to recognize the file name ofthe auxiliary file. Further, at step S111, the file acquisition section102 accesses the disk driving section 11 to read out the auxiliary filefrom the optical disk 7 based on the file name through the buffer 101 toacquire the auxiliary file and supplies the acquired auxiliary file tothe auxiliary file processing section 104. Then, the processing advancesto step S112.

[0181] At step S112, the auxiliary file processing section 104decomposes the auxiliary file supplied thereto from the file acquisitionsection 102 into auxiliary items to extract or acquire auxiliary itemsfrom the auxiliary file. The section 104 supplies the auxiliary items tothe data synthesis section 107. The auxiliary file process is endedthereby.

[0182] Now, the video file process is described with reference to theflow chart of FIG. 20.

[0183] The video file is started, for example, when a master file isread out from an optical disk 7 by the disk driving section 11 andstored into the buffer 101.

[0184] First at step S121, the file acquisition section 102 refers tothe master file stored in the buffer 101 to recognize the file name ofthe video file. Further, at step S121, the file acquisition section 102accesses the disk driving section 11 to read out the video file from theoptical disk 7 based on the file name through the buffer 101 to acquirethe video file and supplies the video file to the video file processingsection 105. Then, the processing advances to step S122.

[0185] At step S122, the header/footer removal section 111 of the videofile processing section 105 (FIG. 15) removes a header and a footer fromthe video file supplied thereto from the file acquisition section 102and supplies the body remaining as a result of the removal to thedecomposition section 112. Then, the processing advances to step S123.At step S123, the decomposition section 112 decomposes a sequence ofpicture items placed in the body supplied thereto from the header/footerremoval section 111 into individual picture items and supplies thepicture items to the data synthesis section 107. The video file processis ended thereby.

[0186] Now, the audio file process is described with reference to theflow chart of FIG. 21.

[0187] The audio file process is started, for example, when a masterfile is read out from an optical disk 7 by the disk driving section 11and stored into the buffer 101.

[0188] First at step S131, the file acquisition section 102 refers tothe master file stored in the buffer 101 to recognize the file names ofaudio files of eight channels. Further, at step S131, the fileacquisition section 102 accesses the disk driving section 11 to read outthe audio files of eight channels from the optical disk 7 based on thefile names through the buffer 101 to acquire the audio files of eightchannels. Then, the file acquisition section 102 supplies the audiofiles of eight channels to the audio file processing section 106.Thereafter, the processing advances to step S132.

[0189] At step S132, the header/footer removal section 121 of the audiofile processing section 106 (FIG. 16) removes a header and a footer fromeach of the audio files of eight channels supplied thereto from the fileacquisition section 102 and supplies the bodies of the channelsremaining as a result of the removal to the KLV decoder 122. Then, theprocessing advances to step S133. At step S133, the KLV decoder 122decomposes the KLV structure of the bodies of the channels suppliedthereto from the header/hooter removal section 121 and supplies theaudio data of the WAVE form of the channels obtained by thedecomposition to the data conversion section 123. Then, the processingadvances to step S134.

[0190] At step S134, the data conversion section 123 converts the audiodata of the channels of the WAVE form supplied thereto from the KLVdecoder 122 into audio data of the channels of the AES3 form andsupplies the audio data of the channels of the AES3 form to the channelmultiplexing section 124. Then, the processing advances to step S135. Atstep S135, the channel multiplexing section 124 multiplexes the audiodata of the channels supplied thereto from the channel multiplexingsection 124 and supplies the multiplexed audio data obtained by themultiplexing to the KLV encoder 125. Then, the processing advances tostep S136.

[0191] At step S136, the KLV encoder 125 delimits the multiplexed audiodata supplied thereto from the channel multiplexing section 124 intounits corresponding to frames of the video data and KLV-encodes themultiplexed audio data corresponding to the frames into multiplexedaudio data of the KLV structure. Then, the processing advances to stepS137. At step S137, the KLV encoder 125 adds a necessary KLV structureof a filler to the KLV structure of the multiplexed audio datacorresponding to each of the frames to produce a sound item. Then, theKLV encoder 125 supplies the sound items produced in this manner to thedata synthesis section 107. The audio file process is ended thereby.

[0192] Now, the synthesis process is described with reference to theflow chart of FIG. 22.

[0193] The synthesis process is started, for example, when requireditems are supplied to the data synthesis section 107. The required itemsare metadata of file units and system items from the metadata fileprocessing section 103, auxiliary items from the auxiliary fileprocessing section 104, picture items from the video file processingsection 105, and sound items from the audio file processing section 106.

[0194] First at step S141, the header/footer production section 131 ofthe data synthesis section 107 (FIG. 17) produces a header and a footerof a file of the standard AV multiplex format and places the metadata offile units from the metadata file processing section 103 into the headermetadata of the header. Further, at step S141, the header/footerproduction section 131 supplies the header and the footer obtained insuch a manner as described above to the header/footer addition section133. Thereafter, the processing advances to step S142.

[0195] At step S142, the multiplexing section 132 multiplexes the systemitems outputted from the metadata file processing section 103, theauxiliary items outputted from the auxiliary file processing section104, the picture items outputted from the video file processing section105, and the sound items outputted from the audio file processingsection 106. Then, the multiplexing section 132 supplies a sequence ofedit units obtained by the multiplexing as a body to the header/footeraddition section 133. Then, the processing advances to step S143.

[0196] At step S143, the header/footer addition section 133 adds theheader and the footer supplied thereto from the header/footer productionsection 131 to the body supplied thereto from the multiplexing section132 to form a file of the standard AV multiplex format and outputs thefile of the standard AV multiplex format. The synthesis process is endedthereby.

[0197] While the series of processes described above can be executed byhardware, it may otherwise be executed by software. Where the series ofprocesses is executed by software, a program, which constructs thesoftware, is installed into a computer for universal use or a likeapparatus.

[0198]FIG. 23 shows an example of a configuration of a computer intowhich a program for executing the series of processes described above isinstalled.

[0199] The program can be recorded in advance on a hard disk 205 or aRead Only Memory (ROM) 203 built in the computer and serving as arecording medium.

[0200] It is otherwise possible to temporarily or permanently store orrecord the program on a removable recording medium 211 such as aflexible disk, a Compact Disc-Read Only Memory (CD-ROM), anMagneto-Optical (MO) disk, a Digital Versatile Disk (DVD), a magneticdisk, or a semiconductor memory. The removable recording medium 211 ofthe type described can be provided as package software.

[0201] It is to be noted that the program may be installed by adifferent method from the method described above wherein the program isinstalled from such a removable recording medium 211 into the computeras described above. In particular, it is possible to transfer theprogram from a download site to the computer by wireless communicationthrough an artificial satellite for digital satellite broadcasting or totransfer the program to the computer by wire communication through anetwork such as a Local Area Network (LAN) or the Internet. The computerthus can receive the program transferred in this manner by means of acommunication section 208 and install the program into a hard disk 205built therein.

[0202] The computer has a central processing unit CPU 202 built therein.An input/output interface 210 is connected to the CPU 202 through a bus201. If the CPU 202 receives an instruction when an inputting section207, which may include a keyboard, a mouse or/and, a microphone, isoperated by the user through the input/output interface 210, then theCPU 202 executes the program stored in the Read Only Memory (ROM) 203.Alternatively, the CPU 202 may load a program stored on the hard disk205; a program transferred from a satellite or a network, received bythe communication section 208, and installed in the hard disk 205; or aprogram read out from a removable recording medium 211 loaded in a drive209 and installed in the hard disk 205 into a Random Access Memory (RAM)204 and executes the program loaded in the RAM 204. Thus, the CPU 202executes processing in accordance with the flow charts describedhereinabove or processing to be performed by the configuration describedhereinabove with reference to the block diagrams. Then, the CPU 202, forexample, outputs a result of the processing from an outputting section206, which may include an Liquid Crystal Display (LCD) unit or/and aspeaker, through the input/output interface 210 as the need arises.Alternatively, the CPU 202 may transmit the result of the processingfrom the communication section 208 or record the result of theprocessing onto the hard disk 205.

[0203] In the present specification, the processing steps, whichdescribe the program for causing a computer to execute variousprocesses, may be but need not necessarily be processed in a time seriesin the order as described hereinabove with reference to the flow charts.Thus, they may include other processes, which are executed parallelly orindividually without being processed in a time series such as concurrentprocesses or processes by objects.

[0204] Further, the program may be processed by a single computer or mayotherwise be processed discretely by a plurality of computers.Furthermore, the program may be transferred to and executed by a remotecomputer.

[0205] In summary, mutual conversion is performed between a file of thestandard AV multiplex format in which video data and audio data areplaced in a multiplexed state in a body and a file of the AV independentformat in which video data and audio data are placed collectively inrespective bodies. Consequently, for example, in order to transmit afile through the network 4 (for file exchange or streaming), thestandard AV multiplex form can be used, but in order to record a fileonto the optical disk 7, the AV independent format can be used.

[0206] Then, where a file of the AV independent format is to be recordedon the optical disk 7, for example, AV independent editing (AV splitediting) can be performed readily.

[0207] Further, in the AV independent format, metadata of frame unitsare placed collectively in one file (metadata file of frame units).Therefore, search for metadata of a frame unit can be performed at ahigh speed.

[0208] Furthermore, the AV independent format adopts the WAVE as acoding system for audio data. Therefore, the data amount of audio datacan be reduced when compared with that in the case of the standard AVmultiplex format adopting the AES3.

[0209] Further, the AV independent format adopts the form of a header, abody, and a footer same as that of the standard AV multiplex format andbesides adopts, for the header and the footer, a header and a footer ofthe same form as that of the standard AV multiplex format. Consequently,any standard apparatus, which is ready for the standard AV multiplexformat, can transmit and receive a file of the AV independent format andwrite and read out the file onto and from a recording medium.

[0210] Furthermore, a file of the standard AV multiplex format has abody in which a plurality of essences such as video data, audio data,user data, and metadata of frame units are placed in a multiplexedstate. Meanwhile, a video file and an audio file in a file of the AVindependent format have only video data and audio data placed in thebody, respectively. Accordingly, a file of the AV independent format canbe considered as a file of the MXF whose body includes a single essence.Contents of a video file or an audio file, which is an MXF file whereina single essence is placed in the body, can be read out by any apparatusthat can recognize an MXF file whose body includes a single essence.

[0211] It is to be noted that the disk apparatus 1 in the presentembodiment writes and reads out a file of the AV independent format ontoand from an optical disk 7. However, a file of the AV independent formatcan be written and read out not only onto and from a recording medium ofthe disk type such as the optical disk 7 but also onto and from anyother recording medium such as a recording medium of the tape type suchas a magnetic tape or a semiconductor memory.

[0212] Further, in the embodiment of FIG. 1, the disk apparatus 1, whichis one apparatus, is composed of the disk driving section 11, formatconversion section 12, and communication interface 13. However, each ofthe disk driving section 11, format conversion section 12, andcommunication interface 13 may otherwise be formed as a singleindependent apparatus.

[0213] Furthermore, in the present embodiment, a file conforming to theMXF is adopted as a file of the standard AV multiplex format. However,not only a file, which conforms to the MXF, but also any file includinga header, a body, and a footer and having multiplex data of two or morearbitrary data placed in the body can be adopted as a file of thestandard AV multiplex format.

[0214] Further, in the present embodiment, multiplexed data of videodata and audio data are placed in the body of a file of the standard AVmultiplex format. However, for example, multiplex data of two or more(streams of) different video data or multiplex data of two or more(streams of) different audio data may be placed in the body of a file ofthe standard AV multiplex format.

[0215] While a preferred embodiment of the present invention has beendescribed using specific terms, such description is for illustrativepurpose only, and it is to be understood that changes and variations maybe made without departing from the spirit or scope of the followingclaims.

What is claimed is:
 1. A conversion apparatus for converting a file of aformat including a header, a body, and a footer, comprising: conversionmeans for converting one of a file of a first format, which includesfirst and second data placed in a multiplexed state in the body, and afile of a second format, which includes first or second datacollectively placed in the body into the other of the files.
 2. Theconversion apparatus according to claim 1, wherein said conversion meansincludes first format conversion means for converting a file of thefirst format into a file of the second format.
 3. The conversionapparatus according to claim 2, wherein the first and second data arevideo data and audio data, respectively.
 4. The conversion apparatusaccording to claim 3, wherein said first format conversion meansincludes: video data extraction means for extracting the video datamultiplexed with the audio data in a file of the first format; videodata coupling means for coupling the video data extracted by said videodata extraction means; and video header/footer addition means for addinga header and a footer of a form same as that of a file of the firstformat to a body provided by the video data coupled by said video datacoupling means to prepare a video file of said video data.
 5. Theconversion apparatus according to claim 4, wherein said first formatconversion means further includes file preparation means for preparing amaster file describing a pointer to the video file.
 6. The conversionapparatus according to claim 3, wherein the audio data in a file of thefirst format are channel-multiplexed audio data formed from audio dataof a plurality of channels multiplexed with each other, and said firstformat conversion means includes: audio data extraction means forextracting the channel-multiplexed audio data multiplexed with the videodata in a file of the first file format; audio data separation means forseparating the channel-multiplexed audio data extracted by said audiodata extraction means into the audio data of the individual channels;and audio header/footer addition means for adding a header and a footerof a form same as that of a file of the first format to a body providedby the audio data of each of the channels to prepare audio files of theaudio data for the individual channels.
 7. The conversion apparatusaccording to claim 6, wherein the channel-multiplexed audio data in afile of the first format are Key, Length, and Value (KLV)-encoded data,and said first format conversion means includes: KLV structuredecomposition means for decomposing a KLV structure of the KLV-encodedchannel-multiplexed audio data extracted by said audio data extractionmeans and supplying resulting audio data to said audio data separationmeans; and KLV structuring means for KLV-encoding the audio data of thechannels obtained by said audio data separation means so as toindividually have a KLV structure; said audio header/footer additionmeans adding a header and a footer to a body provided by the audio dataof each of the channels structured by said KLV structuring means so asto have a KLV structure.
 8. The conversion apparatus according to claim6, wherein the audio data of a file of the first format are data encodedby a first coding method, and said first format conversion means furtherincludes audio data conversion means for converting the audio data ofthe channels coded by the first coding method and obtained by said audiodata separation means into audio data of the channels encoded by asecond coding method.
 9. The conversion apparatus according to claim 6,wherein said first format conversion means further includes filepreparation means for preparing a master file describing pointers to theaudio files of the channels.
 10. The conversion apparatus according toclaim 3, wherein the body of a file of the first format has metadataplaced therein in a form multiplexed together with the video data andthe audio data, and said first format conversion means further includesmetadata file preparation means for preparing a metadata file in whichthe metadata multiplexed in the bodies of a file of the first format arecollectively placed.
 11. The conversion apparatus according to claim 10,wherein said first format conversion means further includes filepreparation means for preparing a master file describing a pointer tothe metadata file.
 12. The conversion apparatus according to claim 2,further comprising recording means for recording a file of the secondformat obtained by said second format conversion means onto a recordingmedium.
 13. The conversion apparatus according to claim 1, wherein saidconversion means includes second format conversion means for convertinga file of the second format into a file of the first format.
 14. Theconversion apparatus according to claim 13, wherein the first and seconddata are video data and audio data, respectively.
 15. The conversionapparatus according to claim 14, wherein a file of the second formatincludes a video file wherein a header and a footer of a form same asthat of a file of the first format is added to the body in which thevideo data are placed collectively, and audio files for audio data of aplurality of channels in each of which a header and a footer of a formsame as that of a file of the first format is added to the body in whichthe audio data of the channel are placed collectively, and said secondformat conversion means includes: video header/footer removal means forremoving the header and the footer from the video file; video datadecomposition means for decomposing the video data of the video fileinto video data of units to be multiplexed with the audio data; audioheader/footer removal means for removing the headers and the footersfrom the audio files; channel multiplexing means for multiplexing theaudio data of the channels of the audio files and outputting resultingchannel-multiplexed audio data; data multiplexing means for multiplexingthe video data obtained by said video data decomposition means and thechannel-multiplexed audio data obtained by said channel multiplexingmeans; and header/footer addition means for adding a header and a footerof a file of the first format to a body provided by the data obtained bysaid data multiplexing means.
 16. The conversion apparatus according toclaim 15, wherein the audio data of the audio files in a file of thesecond format is KLV-encoded audio data, and said second formatconversion means further includes: KLV structure decomposition means fordecomposing a KLV structure of the KLV-encoded audio data; and KLVstructuring means for KLV-encoding the channel-multiplexed audio datainto audio data of the KLV structure in a unit to be multiplexed withthe video data.
 17. The conversion apparatus according to claim 15,wherein the audio data in a file of the second format are data encodedby a second coding method from between first and second coding methods,and said second format conversion means further includes audio dataconversion means for converting the audio data of the audio files fromaudio data encoded by the second coding method into audio data encodedby the first coding method.
 18. The conversion apparatus according toclaim 15, wherein a file of the second format further includes ametadata file in which the metadata are placed collectively, and saiddata multiplexing means multiplexes not only the video data and thechannel-multiplexed audio data but also the metadata.
 19. The conversionapparatus according to claim 13, further comprising transmission meansfor transmitting the file of the first format obtained by said secondformat conversion means through a transmission medium.
 20. Theconversion apparatus according to claim 1, wherein the first format isthe Material Exchange Format (MXF).
 21. A conversion apparatus forconverting a file of a format including a header, a body, and a footer,comprising: a converter for converting one of a file of a first format,which includes first and second data placed in a multiplexed state inthe body, and a file of a second format, which includes first or seconddata collectively placed in the body into the other of the files. 22.The conversion apparatus according to claim 21, wherein said converterincludes a first format converter for converting a file of the firstformat into a file of the second format.
 23. The conversion apparatusaccording to claim 22, wherein the first and second data are video dataand audio data, respectively.
 24. The conversion apparatus according toclaim 23, wherein said first format converter includes: a video dataextractor for extracting the video data multiplexed with the audio datain a file of the first format; a video data coupler for coupling thevideo data extracted by said video data extractor; and a videoheader/footer adder for adding a header and a footer of a form same asthat of a file of the first format to a body provided by the video datacoupled by said video data coupler to prepare a video file of said videodata.
 25. The conversion apparatus according to claim 24, wherein saidfirst format converter further includes a file preparator for preparinga master file describing a pointer to the video file.
 26. The conversionapparatus according to claim 23, wherein the audio data in a file of thefirst format are channel-multiplexed audio data formed from audio dataof a plurality of channels multiplexed with each other, and said firstformat converter includes: audio data extractor for extracting thechannel-multiplexed audio data multiplexed with the video data in a fileof the first file format; an audio data separator for separating thechannel-multiplexed audio data extracted by said audio data extractorinto the audio data of the individual channels; and an audioheader/footer adder for adding a header and a footer of a form same asthat of a file of the first format to a body provided by the audio dataof each of the channels to prepare audio files of the audio data for theindividual channels.
 27. The conversion apparatus according to claim 26,wherein the channel-multiplexed audio data in a file of the first formatare KLV-encoded data, and said first format converter includes: a KLVstructure decomposer for decomposing a KLV structure of the KLV-encodedchannel-multiplexed audio data extracted by said audio data extractorand supplying resulting audio data to said audio data separator; and aKLV structurer for KLV-encoding the audio data of the channels obtainedby said audio data separator so as to individually have a KLV structure;said audio header/footer adder adding a header and a footer to a bodyprovided by the audio data of each of the channels structured by saidKLV structurer so as to have a KLV structure.
 28. The conversionapparatus according to claim 26, wherein the audio data of a file of thefirst format are data encoded by a first coding method, and said firstformat converter further includes an audio data converter for convertingthe audio data of the channels coded by the first coding method andobtained by said audio data separator into audio data of the channelsencoded by a second coding method.
 29. The conversion apparatusaccording to claim 26, wherein said first format converter furtherincludes file preparator for preparing a master file describing pointersto the audio files of the channels.
 30. The conversion apparatusaccording to claim 23, wherein the body of a file of the first formathas metadata placed therein in a form multiplexed together with thevideo data and the audio data, and said first format converter furtherincludes metadata file preparator for preparing a metadata file in whichthe metadata multiplexed in the bodies of a file of the first format arecollectively placed.
 31. The conversion apparatus according to claim 30,wherein said first format converter further includes file preparator forpreparing a master file describing a pointer to the metadata file. 32.The conversion apparatus according to claim 22, further comprising arecorder for recording a file of the second format obtained by saidsecond format converter onto a recording medium.
 33. The conversionapparatus according to claim 21, wherein said converter includes asecond format converter for converting a file of the second format intoa file of the first format.
 34. The conversion apparatus according toclaim 33, wherein the first and second data are video data and audiodata, respectively.
 35. The conversion apparatus according to claim 34,wherein a file of the second format includes a video file wherein aheader and a footer of a form same as that of a file of the first formatis added to the body in which the video data are placed collectively,and audio files for audio data of a plurality of channels in each ofwhich a header and a footer of a form same as that of a file of thefirst format is added to the body in which the audio data of the channelare placed collectively, and said second format converter includes: avideo header/footer remover for removing the header and the footer fromthe video file; a video data decomposer for decomposing the video dataof the video file into video data of units to be multiplexed with theaudio data; an audio header/footer remover for removing the headers andthe footers from the audio files; a channel multiplexer for multiplexingthe audio data of the channels of the audio files and outputtingresulting channel-multiplexed audio data; a data multiplexer formultiplexing the video data obtained by said video data decomposer andthe channel-multiplexed audio data obtained by said channel multiplexer;and a header/footer adder for adding a header and a footer of a file ofthe first format to a body provided by the data obtained by said datamultiplexer.
 36. The conversion apparatus according to claim 35, whereinthe audio data of the audio files in a file of the second format isKLV-encoded audio data, and said second format converter furtherincludes: a KLV structure decomposer for decomposing a KLV structure ofthe KLV-encoded audio data; and a KLV structurer for KLV-encoding thechannel-multiplexed audio data into audio data of the KLV structure in aunit to be multiplexed with the video data.
 37. The conversion apparatusaccording to claim 35, wherein the audio data in a file of the secondformat are data encoded by a second coding method from between first andsecond coding methods, and said second format converter further includesan audio data converter for converting the audio data of the audio filesfrom audio data encoded by the second coding method into audio dataencoded by the first coding method.
 38. The conversion apparatusaccording to claim 35, wherein a file of the second format furtherincludes a metadata file in which the metadata are placed collectively,and said data multiplexer multiplexes not only the video data and thechannel-multiplexed audio data but also the metadata.
 39. The conversionapparatus according to claim 33, further comprising a transmitter fortransmitting the file of the first format obtained by said second formatconverter through a transmission medium.
 40. The conversion apparatusaccording to claim 21, wherein the first format is the MXF.
 41. Aconversion method for converting a file of a format including a header,a body, and a footer, comprising the steps of: receiving one of a fileof a first format wherein first and second data are placed in amultiplexed state in the body and a file of a second format whereinfirst or second data are placed collectively in the body; and convertingone of the file of the first format and the file of the second formatinto the other of the files.
 42. The conversion method according toclaim 41, wherein the conversion step includes a first format conversionstep of converting a file of the first format into a file of the secondformat.
 43. The conversion method according to claim 42, wherein thefirst and second data are video data and audio data, respectively. 44.The conversion method according to claim 43, wherein the first formatconversion step includes: a video data extraction step of extracting thevideo data multiplexed with the audio data in a file of the firstformat; a video data coupling step of coupling the video data extractedby the video data extraction step; and a video header/footer additionstep of adding a header and a footer of a form same as that of a file ofthe first format to a body provided by the video data coupled by thevideo data coupling step to prepare a video file of said video data. 45.The conversion method according to claim 44, wherein the first formatconversion step further includes a file preparation step of preparing amaster file describing a pointer to the video file.
 46. The conversionmethod according to claim 43, wherein the audio data in a file of thefirst format are channel-multiplexed audio data formed from audio dataof a plurality of channels multiplexed with each other, and the firstformat conversion step includes: an audio data extraction step ofextracting the channel-multiplexed audio data multiplexed with the videodata in a file of the first file format; an audio data separation stepof separating the channel-multiplexed audio data extracted by the audiodata extraction step into the audio data of the individual channels; andan audio header/footer addition step of adding a header and a footer ofa form same as that of a file of the first format to a body provided bythe audio data of each of the channels to prepare audio files of theaudio data for the individual channels.
 47. The conversion methodaccording to claim 46, wherein the channel-multiplexed audio data in afile of the first format are KLV-encoded data, and the first formatconversion step includes: a KLV structure decomposition step ofdecomposing a KLV structure of the KLV-encoded channel-multiplexed audiodata extracted by the audio data extraction step and supplying resultingaudio data to the audio data separation step; and a KLV structuring stepof KLV-encoding the audio data of the channels obtained by the audiodata separation step so as to individually have a KLV structure; theaudio header/footer addition step adding a header and a footer to a bodyprovided by the audio data of each of the channels structured by the KLVstructuring step so as to have a KLV structure.
 48. The conversionmethod according to claim 46, wherein the audio data of a file of thefirst format are data encoded by a first coding method, and the firstformat conversion step further includes an audio data conversion step ofconverting the audio data of the channels coded by the first codingmethod and obtained by the audio data separation step into audio data ofthe channels encoded by a second coding method.
 49. The conversionmethod according to claim 46, wherein the first format conversion stepfurther includes a file preparation step of preparing a master filedescribing pointers to the audio files of the channels.
 50. Theconversion method according to claim 43, wherein the body of a file ofthe first format has metadata placed therein in a form multiplexedtogether with the video data and the audio data, and the first formatconversion step further includes a metadata file preparation step ofpreparing a metadata file in which the metadata multiplexed in thebodies of a file of the first format are collectively placed.
 51. Theconversion method according to claim 50, wherein the first formatconversion step further includes a file preparation step of preparing amaster file describing a pointer to the metadata file.
 52. Theconversion method according to claim 42, further comprising a recordingstep of recording a file of the second format obtained by the secondformat conversion step onto a recording medium.
 53. The conversionmethod according to claim 41, wherein the conversion step includes asecond format conversion step of converting a file of the second formatinto a file of the first format.
 54. The conversion method according toclaim 53, wherein the first and second data are video data and audiodata, respectively.
 55. The conversion method according to claim 54,wherein a file of the second format includes a video file wherein aheader and a footer of a form same as that of a file of the first formatis added to the body in which the video data are placed collectively,and audio files for audio data of a plurality of channels in each ofwhich a header and a footer of a form same as that of a file of thefirst format is added to the body in which the audio data of the channelare placed collectively, and the second format conversion step includes:a video header/footer removal step of removing the header and the footerfrom the video file; a video data decomposition step of decomposing thevideo data of the video file into video data of units to be multiplexedwith the audio data; an audio header/footer removal step of removing theheaders and the footers from the audio files; a channel multiplexingstep of multiplexing the audio data of the channels of the audio filesand outputting resulting channel-multiplexed audio data; a datamultiplexing step of multiplexing the video data obtained by the videodata decomposition step and the channel-multiplexed audio data obtainedby the channel multiplexing step; and a header/footer addition step ofadding a header and a footer of a file of the first format to a bodyprovided by the data obtained by the data multiplexing step.
 56. Theconversion method according to claim 55, wherein the audio data of theaudio files in a file of the second format is KLV-encoded audio data,and the second format conversion step further includes: a KLV structuredecomposition step of decomposing a KLV structure of the KLV-encodedaudio data; and a KLV structuring step of KLV-encoding thechannel-multiplexed audio data into audio data of the KLV structure in aunit to be multiplexed with the video data.
 57. The conversion methodaccording to claim 55, wherein the audio data in a file of the secondformat are data encoded by a second coding method from between first andsecond coding methods, and the second format conversion step furtherincludes an audio data conversion step of converting the audio data ofthe audio files from audio data encoded by the second coding method intoaudio data encoded by the first coding method.
 58. The conversion methodaccording to claim 55, wherein a file of the second format furtherincludes a metadata file in which the metadata are placed collectively,and the data multiplexing step multiplexes not only the video data andthe channel-multiplexed audio data but also the metadata.
 59. Theconversion method according to claim 53, further comprising atransmission step of transmitting the file of the first format obtainedby the second format conversion step through a transmission medium. 60.The conversion method according to claim 41, wherein the first format isthe MXF.
 61. A program for causing a computer to execute a conversionmethod for converting a file of a format including a header, a body, anda footer, said program comprising: a conversion step of converting oneof a file of a first format, which includes first and second data placedin a multiplexed state in the body, and a file of a second format, whichincludes first or second data collectively placed in the body, into theother of the files.
 62. A data structure of a file of a format includinga header, a body, and a footer, comprising: a video file wherein aheader and a footer are added to a body in which video data are placedcollectively; audio files for a plurality of channels in each of which aheader and a footer are added to a body in which audio data of thechannel are placed; and a master file describing a pointer to the videofile and pointers to the individual audio files of the channels.